hello,
I try to measure the air velocity in a room.
I did some research on google and I find only sensors that have a high range(I think that in a room there will be a very high speed), and very expensive sensors.
Anyone is aware of the air speed sensors with a low range?(type 0-5 m/s)
Thanks
There are ways to measure the speed based on the self-heating of a fine wire, since more breeze will
cool the wire better. Maybe there's a way to control which direction of air can impinge on a fine wire,
by mounting in a short tube, then use xyz arrangements of tubes?
Ultrasound velocity measurement will have some minimum speed to be practical, don't know what that is.
Laser doppler velocimetry is probably outside the budget range!
Thanks
I found this sensor here
http://it.farnell.com/ist-innovative-sensor-technology/fs5-0-1l-195/sensore-flusso-gas-100m-s/dp/1778049?ost=IST+FS5.01.1L.195&selectedCategoryId=&categoryNameResp=Tutte%2Ble%2Bcategorie&searchView=table&iscrfnonsku=false
But I do not understand if you must purchase the module of arduino associated with it( very expensive) or not.
The wind sensor is a wire resistance device with a heater.
You don't need to buy their electronics, instead you can build your own. That is not a beginner's project.
Do a search on "hot wire anemometer" - you typically use two thermistors - one to measure the cooling of the air moving across it and a second to measure the ambient temperature. Years ago, I did some work with one that was pretty clever - it was a hand held gadget that was a tube - it had a high voltage in it on a center electrode and a special layer inside the tube that allowed it to measure where the ions created from the hv probe in the center fell on the coating in the tube. It worked quite well for low speed air motion testing (we were looking at cabin air flow on the airplanes). It also worked very well to empty your bank account if I remember correctly. You have to be very careful just what and where you are measuring (and how you are measuring the flow) because of all the eddies in the air currents as well as boundary air flow issues. For a simple weather station type measurement, the little ones with the rotating fan or cups work pretty well. You might want to snoop through Mass flow sensor - Wikipedia as well for some tidbits of information.